1. Field of the Invention
Aspects of the present invention relates in general to a solid ink loading apparatus and, more specifically, to a solid ink loading apparatus which disperses and/or breaks up an elastic force pressing a solid ink.
2. Description of the Related Art
A solid ink printing technique has been commercially successful in printers. The technique makes use of a special ink jet printer head provided with thousands of nozzles, each ink jet printer head being about 21 cm (i.e., the width of an A4 size sheet of paper) in length. The ink is normally solid at room temperature and melts in the printer head when the printer head operates at or above 140° C. Compared with liquid ink, a color ink stick which is in a solid state is more durable, prints faster, and exhibits clear colors on all types of papers including expensive bond papers for business use and recycled papers.
Unlike traditional printers, which stop working when printing materials run out, in solid ink printing techniques a user is allowed to add solid color sticks even in the middle of a printing process. In addition, since a separate ink cartridge is not required, the printers may be mass produced without difficulties. Solid crayon matters used as an ink material are low in price. Thus, compared with other laser printers, a solid ink jet printer may be purchased at a 12-20% lower price, and maintenance costs may be lower than half of that of the laser printer.
FIG. 1 illustrates the structure of a solid ink stick feed system used in a solid ink jet printer of a related art. Particularly, FIG. 1 shows the structure disclosed in U.S. Pat. No. 5,861,903. FIG. 2 is a partial top perspective view of an ink stick loading bin assembly of FIG. 1. As shown in FIGS. 1 and 2, the ink stick feed system is largely composed of an ink stick loading bin assembly 16, a yoke 17, a top cover 20, and an ink stick feed bin cover 30. The ink stick loading bin assembly 16 comprises feed chutes 25a-25d in which ink sticks 12 are stored by colors and from which the ink sticks 12 are fed towards melt plates 29a-29d, and at least one key plate 18 to cover the feed chutes 25a-25d. Openings or receptacles 24a-24d are formed in the key plate 18 so that the ink sticks 12 may be inserted therein. The top cover 20 is installed to cover the top of the key plate 18. A feed cover 30 is rotatably installed near the printer sidewalls 21 by pivot arms 22. The yoke 17 is slidably positioned along the upper side of the key plate 18 to assist in the movement of each ink stick 12. Here, the ink stick 12 moves forward on the feed chutes 25a-25d towards the melt plates 29a-29d. 
Ink sticks 12 are inserted into the receptacles or openings 24a-24d in the key plate 18 and are fed down the corresponding ink stick feed chutes 25a-25d to the melt plates 29a-29d, which melt the ink and feed the melted ink into the individual ink color reservoirs within the print head (not shown).
FIG. 3 is a perspective view of push blocks that push the ink stick 12 of FIGS. 1 and 2. As shown in FIG. 3, four push blocks 50a-50d are connected to the yoke 17 through springs 54. The side ends of the yoke 17 are held by the key plate 18 in a track 19 to provide a linear slide along the opposing sides of the key plate 18. At first, ink sticks 12 are put in the feed chutes 25a-25d and the top cover 20 is closed. Then, the ink stick feed cover 30 is interlocked, and the yoke 17 is transferred to where the melt plates 29a-29d are located. The push blocks 50a-50d push the ink sticks 12 towards the melt plates 29a-29d using the elastic force of the springs 54. Thus, contact between the ink sticks 12 and the melt plates 29a-29d is improved.
However, the push blocks 50a-50d each come into contact with the ink sticks 12 reserved on the feed chutes 25a-25d, respectively. Thus, the resisting force from the springs 54 of the push blocks 50a-50d is applied quadruply (i.e., four times), making it very difficult for a user to shut the top cover 20. Moreover, since the feed chutes 25a-25d have a similar length, the user may be required to replenish a color ink stick 12 where printing operations have a high consumption rate.